Turbine, turbine type compressor, and the like rotating machine



Nov. 5, 1946. I K BAUMANN 2,410,769-

TURBINE, TURBINE TYPE COMPRESSOR,AND THE LIKE ROTATING MACHINES Filed Jan. 13, 1944 2 Sheets-Sheet 1 Q WHE 3" 2 I 8 1 4g 4 21 7 M i a Z 2% 35 I 9 9 427 V INVEN TOR.

ATTOR iJEYFS NOV. 5, 1946. BAUMANN 2,410,769

TURBINE, TURBINE TYPE COMPRESSOR, AND THE LI EKE ROTATING MACHINES Filed Jan. 13 1944 2 Sheets-Sheet 2 a W %k w Bwl 1 N FIG. 4.

INVEIY To)? 4 Mu Luz.

II rroRMe-Y Patented Nov. 1946 TURBINE, TURBINE TYPE COMPRESSOR, AND THE LIKE ROTATING MACHINE Karl Baumann, Mere, Knutsford, England, an

signer to Metropolitan Vickers Electrical Company Limited, London,

Great Britain Application January 13, In Great Britain May 4 Claims. (Cl. 230-122) Thi invention relates to turbines, turbine type compressors and the like rotating machines of the kind wherein during operation there is axial reaction between certain of the relatively rotating parts which needs to be balanced wholly.

or in part other than by means of thrust bearings. In the case of steam turbines of the reaction type, it has been a common practice to deal with the axially-directed reaction between stationary and rotating parts by means of so-called balancing pistons mounted on the rotor and running with fine clearance distances from the stator,-such balancing pistons, for instance, presenting an annular area to the pressure fluid sufficient to balance the axial-force exerted by fluid at the same pressure on the turbine rotor. The present invention, however, concerns more particularly but not exclusively compressor and gas turbine plants and is notably applicable to the high speed axial flow or turbine type compressors forming a part of such plants or serving as superchargers for internal combustion engines of the reciprocating type. It is frequently also a requirement in the case of such a plant to minimise the space occupied thereby, and particularly the axial length, for which reason balancing pistons of the full rotor diameter and located axially beyond the confines of the working rotor are not convenient.

According to the invention, balancing devices are accommodated substantially within the axial length ofthe inner bladed drum or rotor cylinder of the turbine or compressor, and involve a plurality of faces of rotor surface of annular or frusto-conical or like form on which high pressure fluid is caused to bear, giving thrusts in the same sense for the several faces. By the use of a plurality of such faces, the requisite total area is attained, although the outside diameters of the several faces are necessarily less than the drum diameter.

Conveniently, thrust faces are provided at each end of the rotor, that or one of them at the high pressurev end arising as one face of a radially extending annular recess formed in the rotor, the recess being divided in the general direction of a plane at right angles to the axis of the rotor into two chambers by a stationary diaphragm supported by an axially extending cylindrical sleeve which enters the recess axially at its outer periphery from the high pressure end of the machine. Fine running clearances are provided at the inner annular face of the diaphragm and atthe inner and outer cylindrical surfaces of the sleeve, and the two chambers are put into com- England, a company of 1944, Serial No. 518,163

munication respectively with high and low pressure fluid sources conveniently by ducts in the sleeve, The low pressure fluid source may be the atmosphere.

, At the low pressure end of the rotor the thrust face thereof is more readily provided as the rear wall of a disc or the equivalent terminating an annular recess extending towards the low pressure end of the machine, into which recess a stationary piston having an annular face protrudes with fine running clearances at its inner and outer cylindrical faces, the recess communicating by means of a duct or ducts in some part of the rotor body with a source of high pressure fluid,

for instance with the aforesaid high pressure chamber of the recess at the high pressure end of the rotor. It will bewell understood that in locations where fine running clearances for fluid sealing are here called for, known types of labyrinth glands may be used. The axial counterthrust obtained by the invention need not necessarily be of such magnitude as to balance the thrusts on the rotor due to the several fluid pressures utilised but may have any desired magnitude in terms of the pressures utilised, the thrust to be balanced or partly balanced being in part due to the fluid pressure at the discharge end of the machine and the associated areas subjected to the pressure there, in relation to the fluid pressure at the intake end of the machine and the areas subjectedto the pressu e there.

In the accompanying drawings- Figure 1 is a diametrical longitudinal section of a part of a machine embodying the present invention.

Figure 2 is a transverse section on the line 2-2 in Figure 1.

Figure 3 is a detail section on Figure 2.

Figure 4 is an enlarged diagrammatic section of the upper half of the structure shown in Figure 1, with portions thereof broken away.

the line 3-3 in The machine shown in the drawings may be assumed by way of example to be an axial flow air compressor forming part of internal combustion plant which may be employed for the propulsion of aircraft or other craft.

In the drawings, at i and la are shown parts of the blade-carrying rotor of the compressor at or near the discharge and intake ends respectively. It is assumed that the parts I and la are portions of a single rotor drum, but the inven tion is not limited in this respect since they may be parts of two independent rotors such as in two machine comprising high pressure and low presat or near the intake end of cylindrical surface sure units connected in series and usually. but not necessarily, in axial alignment.

The blades carried by the rotor are indicated at 2, and the guide blades carried by the stator are indicated at 3, whilst one of the blades of the final stage of stator blading is-indicated at 4. At 5 is shown part of the stator casing carrying the blading 4 and 3 and further stages to the right, whilst 50 is the part of the stator casing or drum the compressor carrying blading 3 co-operating with blading 2 carriedon the part Ia of the rotor.

A 8 is shown an annular stator member definin with the left-hand end of the stator portion 5 the discharge or outlet of the compressor through which the air flows from right to left as indicated bythe arrow 1, whilst the normal thrust on the rotor is in the direction of the arrow 8.

The part I of the rotor is diagrammatically shown as being carried by a disc member 9 having a hub l fixed to a shaft indicated at H, whilst the right-hand part la of the rotor is shown as being carried by a disc l2 the hub of which is also fixed to the shaft H, the latter being assumed to be driven from its right-hand end. The lefthand end of this shaft is carried in a thrustsustaining bearing which is supported by a transverse wall 52 associated with the annular stator member 6, whilst at the right-hand end the shaft is carried in a thrust-sustaining bearing 53 associated with another stator member which is diagrammatically indicated at I 3; the wall 52 and member l3 and the stator connecting them closing the entire casing containing the rotor, and being supported by the relatively fixed stator member 6 and the inlet casing member 54.

As part of the present invention the rotor part I is provided with a thrust face I 4 or piston in the form of a. disc l5 carried by or integral with a the hub I 0,'the periphery of the disc having an integral or attached cylindrical portion I6, the outer surface of which is adjacent the inner of an axial cylinder I! bolted at I8 to an integral flange IS on the annular member 6. Labyrinth packing 20 is provided between the inner surface of the member I! and the outer surface of the cylinder l6, whilst labyrinth packing 2| is provided between the outer surface of the axial stator cylinder l1 and the inner surface of the part i of the rotor. There is bolted at 22 to the right-hand end of the stator cylinder member H a disc 23 at the inner periphery of which is a stator cylinder portion 24 within which is a rotor cylinder portion 25 disc or wall 26 bolted at 21 to the rotor part I. Labyrinth packing 28 is provided between the cylinders 24 and 25. As indicated by the arrow 29 high pressure air passes radially inwards through the annular gap 30 between the left-hand end of the rotor part I and the right-hand end of the annular member 6. The stator cylinder member I1 is provided around it with a plurality of axial passages 3| so that the high pressure air acts upon an annular area of the thrust face l4 the radial extent of the area being indicated by the arrow 32 (Fig. 4);

. The rotor supporting disc 9 has in it one or more perforations 33 through which the high pressure air can pass from the chamber 34 provided between the thrust disc l5 and the stator- -disc 23, to flow to the low pressure end of the turbine as hereinafter described.

The space or chamber 35 between the stator disc 23 and rotor disc 26 is connected to a source of air at lower pressure in any desired manner, but

carried by a conveniently by the provision of further holes 3la drilled in the axial direction through the stator cylinder member I? and the external flange of the disc 23 and the internal flange I9 01 the stator annular member 6.

The direction of thrust due to the higher pressure on the thrust disc I4 is indicated by the arrow 36 (Fig. 4).

The air leaving the perforations 33 in porting disc 9 passes, as indicated by the in the axial direction within the rotor I, la, and enters, as indicated by the arrow 38, ports 39 in the supporting disc 12 of the right-hand end la of the rotor. Into the annular space 40, axially to the supshown at 4|, at the periphery of an annular disc member 42 secured to or forming part of the stator member I 3. At the left-hand end of the cylinder member 4| is an annular disc 42a bolted to which is ahollow cylinder 43 between which and the inner surface of the rotor part la is labyrinth packing 44. At theinterior periphery of the disc 42a is a cylinder portion 45 between which and a cylinder 46 on the rotorhub is labyrinth packing 41. The cylinder 4| is provided with ports 48 connecting to atmosphere through ports 55, or other source of air at low pressure through a gap 56 at the intake end of the rotor, the space 49 between the discs 42 and 42a, the direction of any s that may flow from the space 49 being indicated by the arrow 50.

I claim:

1. In a turbine or compressor or like rotating machine of the kind referred to and having an inner rotor drum bladed on its outer surface, thrust balancing devices accommodated substantially within the axial length of the inner bladed rotor drum, comprising means within the drum and rotating therewith which provide a plurality of faces of rotor surface of annular form to which the counterpart of such thrust, said means and member forming chambers between them, and means for conducting high pressure fluid to the respective chambers.

2. A turbine or compressor or like rotating machine of the kind referred to having balancing devices as claimed in claim 1, wherein the high pressure fluid is caused to bear in a thrust balancing direction on a rotor face at the high pressure end said member comprising a stationary diaphragm within an annular recess in the rotor and having fine running clearances therewith, a stationary sleeve extending with fine running clearances within the drum and supporting said diaphragm and duct means within said sleeve for conducting the high pressure fluid into the space so defined between the opposing stationary and rotating faces.

3. A turbine or compressor or like rotating machine of the kind referred to having balancing devices as claimed in claim 1, wherein the high pressure fluid is caused to bear in a thrust balanc ing direction upon a rotor face at the low; pressure end of the rotor said member comprising a stationary piston within'an annular recess in the rotor and having flne running clearances therewith, and duct means for conducting the high pressure fluid to the space thusdefined by the arrow 31,

opposing stationary and rotating, facesthrough v the high pressure end, the high pressure fluid chamber at the high pressure end of the machine having an outlet leading to a passage within the rotorand the high pressure chamber at the low pressure end of the machine having an inlet communicating with said passage.

KARL BAUMANN. 

